<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en">
<head>
	<meta http-equiv="Content-Type" content="text/html;charset=UTF-8">
	<title>Document</title>
	<style type="text/css">
		.box1{
			width: 400px;
			height: 400px;
			border: 1px solid red;
		}
		.box2{
			width: 200px;
			height: 200px;
			border: 6px solid red;
			padding: 95px;
		}
		.box3{
			width: 0px;
			height: 0px;
			padding: 200px;
			border: 1px solid red;
		}
	</style>
</head>
<body>
	<div class="box1">第1个盒子</div>
	<div class="box2">第2个盒子</div>
	<div class="box3">第3个盒子</div>
</body>
</html>